Automobile wheels or transmission pulleys are formed into a disc part and a peripheral rim part which is roughly perpendicular to the disc part in a unified body. Since the rim has an annular part projecting outwardly, the wheel can be not manufactured only by a single forging process. Thus, the prior method exhibited in Japanese Patent Publication No. 3-2574 has produced a disc-shaped prototype to the final shape by forging, except an annular part. The peripheral annular part is then formed into a determined rim part by rolling formation. The conventional method of producing a light alloy wheel requires separate processes, one of which is a forging process for finishing the disc part to its final shape and the other is a spinning process for finishing the rim part to its final shape. Thus, in the conventional manufacturing line, it is necessary that a forging apparatus and a spinning apparatus are used separately. Moreover, it is necessary to store semifinished items between the forging process and the spinning process.
Accordingly in the prior method, a large space is required to manufacture the wheel. And different rams are required for each process. Moreover, since the wheel is finished to its final shape through at least two processes, it takes a long time to produce the wheel in its final shape. Therefore, a light alloy wheel can not be produced at low cost.
An object of this invention is to provide a method of shaping a wheel, that includes a disc part and a peripheral rim part which are made from materials highly subject to plastic deformation, in a unified body in a small space occupied by apparatuses for shaping a disc part and for shaping a rim part. Another object of this invention is to provide a method of shaping a wheel which can save process time. A still further object of this invention is to provide a method which can reduce the number of rams.